Generally, electric motors are classified into two types: i.e. inner-rotor type motors and outer-rotor type motors. During operation of the inner-rotor type motor, the rotor is rotated within the stator of the motor. Whereas, during operation of the outer-rotor type motor, the rotor is rotated around the stator of the motor.
Moreover, the silicon steel of the motor stator is usually an integral part. FIG. 1A is a schematic top view illustrating a conventional inner-rotor type motor. As shown in FIG. 1A, the motor 1 comprises an outer frame 10, a stator 11 and a rotor 12. The stator 11 and the rotor 12 are accommodated in the receptacle within the outer frame 10. The stator 11 has a ring-shaped structure. The rotor 12 may be connected with a load (not shown). In addition, the rotor 12 is disposed within the ring-shaped structure of the stator 11.
FIG. 1B is a schematic enlarged fragmentary view of the circled portion of the motor as shown in FIG. 1A. Please refer to FIGS. 1A and 1B. The stator 11 comprises a housing 13 and a silicon steel sheet 14, which are integrally formed as the ring-shaped structure. In addition, plural T-shaped tooth members 15 are formed on the ring-shaped stator 11, and a coil 16 is wound around the base parts 150 of the T-shaped tooth members 15. When the motor 1 is turned on, electricity flows through the coil 16 to generate a magnetic field. Since the magnetic field of the rotor is opposite to the magnetic field of the stator, the two magnetic fields repel each other to result in a continuous rotation of the rotor 12 and the load connected thereto.
Conventionally, the housing 13 and the silicon steel sheet 14 of the stator 11 are firstly integrally formed by a plastic injection molding process, and then the coil 16 is wound around the base parts 150 of the T-shaped tooth members 15. As known, the outer ring 17 and the narrow space between any two adjacent T-shaped tooth members 15 become hindrance from winding the coil 16 around the base parts 150. In addition, if the coil 16 is contacted with the T-shaped tooth members 15, the covering of the coil 16 is readily damaged. Since the process of internally winding the ring 17 is time-consuming, the throughput of the silicon steel assembly 1 is low. For increasing the throughput, the number of winding machines needs to be increased. In other words, the conventional method of fabricating the silicon steel assembly is not cost-effective and the product competitiveness is unsatisfied.
For obviating the drawbacks encountered from the prior art, there is a need of providing a silicon steel assembly and an assembling method thereof.